Evacuated drum drying machine



3 Sheets-Sheet l L. S. OVERTON EVACUATED DRUM DRYING MACHINE July 8,1952 Filed Sept. 5, 194a 37227727? Zs LE 3. 0v5er0/v .20 ymw 5 EVACUATEDDRUM DRYING MACHINE July 8, 1952 I L. s. OVERTON 3 Sheets-Sheet 2 FiledSept. 3, 1948 IYVEJYfUZ LYLE 6. OVEETO/V y 1952 L. OVERTON 2,602,498

EVACUATED DRUM DRYING MACHINE Filed Sept. 5, 1948 5 Sheets-Sheet 55 ZYLE 8. 01/5270 Patented July 8, 1952 EVACUATE DRUM DRYINGVMACHI'NEDowagiac, Mich, assignor to" Lyle S. Over ton;

.Overton Machine Company, Dowagiac, Mich, a

' corporation of Michi Application September 3, 1948, Serial No. 47,649

This invention relates to a vac'uum type drum drying machine. Morespecifically-the invention relates to a vacuumdrying machine inwhich thedried material may be removed without breaking the vacuum and in whichadjustment of the moving parts may be made from suitable control outsidethe machine. I

It is an object of this invention to providea vacuum drying machinecapable of continuous operation. I

Another object of the invention is to provide a drum drying machine witha doctor blade in which proper tension is maintained by the useof vsprings.

Another object of the invention isto, provide a vacuumdrying machinefrom whichboiled or decomposed solid material may be rejected withoutstopping operation or breaking the vacuum."

A further object of the invention is to provide a vacuum drying machinein which all controls are located outside the vacuum chamber.

Other and become apparent to those skilled in the art from the followingdetailed description of the annexed sheets-of drawings which disclosepreferred embodiments of the invention.

The-above objects 1 are accomplished by the apparatus of this inventionwhich comprises in combination a gas-tight receptacle, means forevacuating the receptacle, rotatable cylindrical drums inside thereceptacle, means for introducing liquid to the surface of the rotatabledrums, means for rotating and heating the cylindrical drums, doctorblades'for removing dried solid material from the rotatable drums;collectors for picking up the solid material scraped from the drums bythe. doctor blades-and transferring the material to a=conveyor which inturn transfers it to a double:hopper'unloader. As will more fully appear hereinafter, the doctor blades have a spring meansfor-i maintainingtension against the rotatable: drums; the collector means may be swungout of position in the event the solidmaterial coming over on the drumis not of suitable quality; and the unloader is arranged for continuousoperation of the machine without breaking 'theflvacuum. All movingpartswithin the vacuum chamber are controlled by suitable switches,- wheelsand levers on the outsid of the apparatus. 5 v on the drawings:

Figure 1 is a transverse cross-sectional view, wlthparts inend'elevation, of the apparatus taken along the line 1-1 of Figure 2;.v

Figure 2 is aside elevational view of the machine;"""'

further objects of the inventionwill I 3 Claims. (01. 159-12) Figure3.is an em y; Figure 4 is IV-IV of Figure 3;

Figure 5 is a partial cross-sectional view'o'f f seal arrangement forpreventing leakage with the vacuum chamberwithout interfering with operation of a rotatable control shaft projecting through the casing of themachine;

Figures 6, 7 and 8 are cross-sectional views of Y the unloader takengenerally along the line v the various posi- VI-VI of Figure 2 butshowing tions of the dumping valves.

As shown on the drawings;

In Figures 1 and 2 numeral 10 with this invention. Receptacle II), whichis gastight, rests on supporting members II which are in turn maintainedby I-beams l2. Receptacle I0 consists 'ofbody l3 and end plates 14.Vapor take-off 15 (Figure 2) extends from the end of receptacle H) to acondenser 16, Water coming through an condenser It by direct contact. Avacuum pump (not shown) is attached to a conduit 18 and.

serves to evacuate receptacle l0.

Referring particularly to Figure designates cylindrical drier drumswhich may be rotated by power unit 2| (Figure 2). The drums l9 cooperateto define a nip and are internally heated In Figure l, the illustratedleft-hand drum l9 rotates clockwise and the right-hand drum l9 ro-vtates counterclockwise to collect liquid from the nip troughand maintaina film thereon which has a thickness gauged by the nipbetween the Thefilms of material onthe surfaces of these drums are dried and scrapedoiflof. the 26 in holder bars121. The the scraper is deposited oninclined plate apron 28 from which it passes to troughs 29 equipped withscrew conveyors to.

rolls.

dried film material from move the material to chutes v3| at the frontend of the tank. The chutes discharge intotrough 32..

Each plate apron 28 is hinged along its lower edge to the adjacenttrough 29 and may be swung outward from drums I9 by manipulation of acontrol lever 33 (Figure 2) a sectional view taken alongthelinedesignates a" vacuum tank receptacle equipped in accordance inletconduit l1 condenses vapor in' 1, numeral I9 trough therebetweenbysteam-introduced through pipe 22 (Figure 2) which is connected- Numeral24 designates the inlet pipe As shown in dotted :lines in' Figure l, theoutward positions of the plate collectors 28 will provide a gap betweenthe drums l9 and the troughs 29 so that undesired material scraped fromthe drums by the scrapers 26 will not enter the troughs to contaminatethe desired product. The outside operating levers for the collectorsthereby givethe operator full control over the acceptance or rejectionofanyportion ofthe product scraped from the drums Without breaking thevacuum in the tank I 0.

The pressure of doctor blades 2 6 on drums l9 may be altered by means ofcontrdLwheels i' l'v which actuate screw linkages to rock the holderbars 21 in their pivot mountings. I whereby such linkages are maintainedin vacuum tight relation with the interior of receptacle Ill The" meansHopper valve 45 is then closed by manipulation of handle 45a and thecycle is ready to be repeated. Thus, the machine may be operated tocontinually discharge its product into hopper 42 without breaking thevacuum seal and the product can be intermittently, discharged in batchesof 'controlled size. to fill bag's; barrels or the like containers.

While the positions of the blade bars 21 can be easily controlled fromoutside the tank In by mani'puIation. of." the hand wheels 34, thesebars will be more fully discussed hereinafter with reference to Figure5.

The material which discharges through the chutes 3! is collected in thetrough 32 and moved by a "screw. conveyor" 32a: thereon toward thetransverse central" portion of the front end or the tank mill 35 reducethe solid material tonne powdery form at this point. The material maythen'be raised by elevator 38 to a'conduit 3Tcontaining, a screwconveyorf'fla lucatednear the; top of the vacuum chamber. Both screwconveyors 32a and.

3Ta'are driven byelectric mo'tors'looated outside the vacuum chamber asdesignated by numerals 38and 39, respectyely; The screw conveyor rmtransfers the" solid material. through conduit. 31 to an'unloader 41,the operation o'f-which may.

be more fully understoodiby' referenceto F ures 6, 7 and.8.

The, unloader consists of two superimposed hoppers, the upper one 42emptying into the lower one 43; The: hopper 42 is opened upon re-'lease, ofa valve mechanism 44' and the hopper 43"is opened upon releaseof a valve. mechanism 45. conduit 46. from a. source of vacuum (notshown) is. provided to evacuate hopper'43, and f vacuum. in. the hopperiscontrolledby avaIv'eI 48. A conduit 41 containinga valve49alsocoinmunicates with. hopper 43 and may be. opento. theair or may beconnected to. an inertgas such. ascarbonldioxide or nitrogen.

The various positions V and 45' (Figures-6, 7 and 8-) illustrateatheoperationof. the. unloader. :I-nFigure 6,; hopper 42 is under vacuumexisting in the' tank 10'; While hopper 43is underatmosphericpressure.Vacuum in. thehopper'fl. plus the valve linkageholds valve44in;closedposition. In order toempty hopper 42gwithout loss of vacuumfromctank H1, valve: 4921s; closed. and? valve 48 is: opened; in. orderto=-place hopper 43 undervacuum. Thistevacua ti'onl ofhopperi 430131115.the: valve: linkage. holds valve. 45: closed position. As

tially equal the weight Of the solid. material inv the-hopper: 42' openstrailed. iniFi'gureplT-z valve 45;-plus:the valveillnkage',willisupportrthe; weightofithe materialin hopper 43 'When..liope--pen-.42 is; emptied, happen-valve 4-4 is closed-by actuation. oi thehandle-44a; and vacuum valve-.4 8: is: closed. Valve 49 is then: opened.tn bleedi air:- on inert gas intcxhopper; 43. IIEhe pressure off.

the-:airorr inert gas then acts to maintain-hopper valve; 44 in closedposition;v and since the: air::pnes:.

sures; on both. sides v of. hopper. valve 45:1arersuhi-i stantially:equal,- .the, weight. of. the solid; material: then opens: valve of.the. valve mechanisms soon as; the .pres: sure both-sides .of.thethopper 44'. are substane hopper: valve; 44' and: the r solidamatterpasses down .tcr hopper 43; as H1113? I Atmospheric" pressure:

45 as illustrated: in; l ligure 18;.

arequite rigid and do not compensate for variations in. blade pressuresalong their lengths caused, fhrfexample, by uneven wear and variationspermitted by manufacturing tolerances. In orderto effect and maintainuniform loading alongthe lengths of the doctor blades 26, the blademountings disclosed in Figures 3 and 4 are used. As illustrated therein,the blade 26. is

I0. It is, convenient to have hammermeans oiscrewmembersxfill. v I

The; bearing of Figure :5Kis. easily -fabricateli. since close;tolera-nces: are not necessary.:, iThe-; pressure-,ofidisk member 6|.against. the carbon-. ring seal=6;5: forms a gas-tight bearing andz the,rounded countour of the 'pand to -continuously 7 loading. will becontinued. even. after wear clamp-ed betweenr'th er lip 23m of" the: bar2 1- anda rigid lock" bar-51' attached-to the lip 2%; by a-se'--- ries:of cap screws 5t in equally spaced relation. As in'Fi'gure I, the bar51" underlies" the; upperportion of the blade overlies this portion andan adjacent blade porition not covered by the bar. In order to uni.-

form'ly'loadthe blade 26 against the drum l9. small" coil springs SZ'seated'in holes 2Tb in the lip 21a are adjustably loaded by plugs 54'threaded within. holes to locally load'the blade. These springs act; onthe; uncovered .portionlof' the blade "in spacedrelation from theportion. co v;

ered by the lock bar: 5|.

These springs. 53 are. positioned. about two.

inches apart. along. the length of.v the lip 21a and,

as, well. as. power. on-

If itisdesired to; have. shaft. 58. power; driven-l. wheel -58zmay beexchangedfor a: pulley.

6 I- is: rigidly attached to shaft. 58:1and is slidably attachedtmshaft;5.8; by means :015 6.3.

so as.=.to-. be capable of longitudinal movemerm A compression; spring.64; disposed. around the: 52.: exerts .aprgssme shaft; between. discs-GI. and to .:forcerboth;disks '6! and. 62'. againstcarbomring: seal;members; 35:. These carbon ring-seal. members 6:55am disposedin ahousingifi fi- 'closedgbyn...

top plate '61:; 'Iiopaplat'e; .61.: is secured touthe housing 66 bymeans housing :66: is secured;

to the body-member. 1|

shaft 58 to seat itself naturally'duev tonthanressurejof springfit, 1

.. In; order to facilitate maintenance H have been provided asshowndniligures and. 2. Sight glasses designated; by numeral 1-2. have beenprovided in various parts of the apparatus;

while the lip 21a Control; wheels fl bearings such as: that As: shownin; Figure; 5:, rotatable; shaft. whichof. screw: members :68: The

disk member 6!. enables,

Drain plug 13 is located at the base of the apparatus as shown in Figure2.

From the above description it may be seen that this invention provides acontinuous vacuum drying machine in which all movin Parts are controlledfrom outside the vacuum chamber. and in which the desired solid materialmay be collected and removed and the undesired solid material may beselectively rejected without breaking the vacuum. This machine isparticularly useful in drying milk Without giving the dried milk powdera boiled or cooked flavor since lowerdrying temperatures can be used dueto the maintainedvacuum.

It will be understood that construction may various details of drum, aconveyor in said receptable spaced from said blade and drum, a swingableapron below said blade for receiving solid material removed by saidscraper blade from said drum and for transferring the solid material tothe conveyor, a rod connected to said apron extending to the outside ofsaid recepatcle, a handle on said rod for rotating the rod to swing saidapron toward and away from said drum to selectively transfer material tosaid conveyor and to prevent such transfer, and means for removing solidmaterial from said receptacle.

2. In a vacuum drum drying apparatus having a rotatable drier drum, theimprovements which comprise a r'ockably mounted holder bar disposed inpro ty to the surface of said drum and extending along the length of thedrum, means operable from outside of said apparatus for swinging saidholder bar, a scraper blade, a clamping bar cooperable with said holderbar to clamp said blade therebetween with one elongated lateral edge ofsaidblade projecting beyond said bars, a plurality of closely spacedspring means carried by said holder bar outwardly from the clamping barto act on said blade at spaced intervals along the length thereof, anadjusting device for each spring carried by said holder bar toselectively load the spring for resiliently urging said blade againstsaid drum to maintain equal scraping conditions 'drum, means forintroducing a be varied through a wide range without departing from theprinciples of -this invention, and it is,

along the length of said blade, an apron mounted alongside said drumbelow said blade to receive 'material scraped from the drum by saidblade, a conveyor receiving material from said apron, a pivot mountingfor said apron, and means extending to the outside of said apparatus andconnected to said apron for swinging the apron away from the drum toprevent trans- -fer of material to said conveyor.

3. A vacuum drying apparatus comprising a gas-tight receptacle, arotatable drier drum disposed in said receptacle, means for rotatingsaid film or liquid material onto the periphery of said drum, a scraperblade peripherally displaced from said last mentioned means for removingsolid material from the drum, a conveyor disposed beneath said drum forreceiving gravity flow of solids from said blade, a swingable plateapron disposed between said conveyor and said blade, and handle meansextending exteriorly of said receptacle and connected with saidswingable plate apron for actuating said apron to alternate positionsincluding a first position adjacent said blade for conveying materialfrom said blade to said conveyor, and a second position spaced from saidblade to interrupt said communication between said blade and saidconveyor.

LYLE S. 'OVER'ION.

REFERENCES CITED The following referencesare of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 711,719 Ekenberg Oct. 21. 1902879,490 Rasmussen Feb. 8, 1908 960,857 Eggert June 7, 1910 1,200,117Johnson et al. Oct. 3, 1916 1,249,177 Oppenhauser Dec. 4, 1917 1,408,483Stephens Mar. 7, 1922 1,501,513 Boberg July 15, 1924 1,501,514 BobergJuly 15, 1924 1,566,358 White Dec. 24, 1925 1,726,751 Miles Sept. 3,1929 1,933,819 Miles et al. Nov. 7, 1933 2,102,607 Baker Dec. 21, 19372,250,852 Bertelsen et al. July 29, 1941 2,314,316 'Schlesman Mar. 16,1943 2,325,203 Hayes July 27. 1943 2,326,512 Andrews Aug. 10, 19432,338,606 Voorhees Jan. 4, 1944 FOREIGN PATENTS Number Country Date349,337 German Feb. 28. 1922

